Minnesota Focus Owners Club

help! just put in a new alt n the battery light is on! I checked and tested the battery and that passed, I checked and tested the alternator and that passed as well! All my wire connections r tight and together correctly! The light came on after 1 minute after starting the car up! Idk what could cause that all I did was buy a new alternator and installed it! The car has correct voltage and the alternator is working properly! Any suggestions?


2000 ZX3- OBX Racing full exhaust, 65mm TB, Bosch O2's, Bosch Plugs and wires, AEM full CAI, ADR 17" rims, tint, led underglow, k6 led turn signal mirrors, tinted taillights, twin halo projector style headlights with 6000k HID kit, full Alpine sound system and euro racing strip and silver painted zetec valve cover, silver gauge cluster, billet grill, clear side markers with white led bulbs!

Is it coming on at idle or while driving? If it's while driving your serpentine belt tensioner could be bad and could be allowing the belt to slip, thus the alternator would not be worki and charging correctly. Also the notorious alternator pigtail could be bad, that's also super common. Have you used a voltmeter to check loads?

check the fuse panel in the engine bay. I don't remember which fuse it is, but I believe its a 15A towards the front of the fuse box.

FocusMech.73155 wrote:check the fuse panel in the engine bay. I don't remember which fuse it is, but I believe its a 15A towards the front of the fuse box.

I was having the same problem, and it turned out to be that fuse.

All I have done so far is tested the battery and the alternator and they r both good! Alternator is new and the battery tested good and its only a couple of months old! I get good voltage off both too! So idk. Maybe its the alternator!

fuuuse

Ok!